(a) Field of the Invention
The present invention according to an exemplary embodiment relates to an electric pump for a vehicle, and more particularly to an electric pump for a vehicle that exhausts a coolant that is leaked out through a sealing portion, e.g., like a mechanical seal, where the coolant is hereinafter called ‘leachate’ for convenience.
(b) Description of the Related Art
Generally, a pump circulates coolant through an engine and a heater thereof so as to cool the engine and so as to heat the interior room. The coolant that is pumped from the pump circulates the engine, the heater, or a radiator to exchange the heat and is returned to the pump. The pumps are typically divided into a mechanical type pump and an electric type pump.
Mechanical pumps are connected to a pulley that is fixed on a crankshaft of the engine to be rotated by the crankshaft (i.e. the rotation of the engine). Accordingly, the coolant flux that is pumped from the mechanical pump is determined by the rotation speed of the engine. However, the coolant flux that is necessary in the heater and the radiator is determined independently from the rotation speed of the engine. Thus, the heater and the radiator are abnormally operated in an area that the engine speed is low. That is, the engine speed must be raised to normally operate the heater and the radiator. This causes fuel consumption of the vehicle to rise as a result.
The electric pump is operated by a motor that is controlled by a control apparatus. In this case, the coolant flux can be controlled independent of the engine speed. However, since the components of the electric pump are operated by electricity, it is important that the component of the electric pump has a significant waterproofing. As a result of the ability to control the flux produced by the electrical pump, vehicle manufactures have begun to use them in place of the mechanical pumps. Consequently, various arts have been being developed for improving the performance of the electric pump and the durability thereof.
In general, an electric pump, like the one described above, is divided into a motor room that is composed of a stator and a rotor and a pump room that pumps the coolant. More specifically, a pump body forms the motor room and a volute housing forms the pump room.
Here, the motor room and pump room can be separated by a sealing member, such as a mechanical seal, that is used to prevent the coolant from passing from the pump room to the motor. The sealing member is typically disposed on a shaft that is connected from the motor room to the pump room. Additionally, an impeller is disposed in the pump room to be fixed on the shaft so as to pump the coolant.
Also, a leachate exhaust passage is formed in the pump body of the electric pump so as to exhaust the leachate that is leaked from the motor room through the sealing member of the pump room.
However, the leachate exhaust passages formed in a conventional art exhaust the leachate that is leaked from the pump room to the motor room through the sealing member. Thus, conversely the outside fluid (e.g., water) can flow into the pump room or the motor room through the leachate exhaust passage such that several problems, such as the insulation deterioration of the motor and the bearing corrosion, can arise.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.